Multi-spacecraft observations of ULF waves during the recovery phase of magnetic storm on October 30, 2003  

作　　者：YongFu Wang  SuiYan Fu  QiuGang Zong  Biao Yang  ZuYin Pu  Lun Xie XuZhi Zhou 

机构地区：[1] Institute of Space Physics and Applied Technology, Peking University, Beijing, 100871, China [2] Center for Atmospheric Research, University of Massachusetts Lowell, Lowell, MA 01854-3629, USA

出　　处：《Science China(Technological Sciences)》2008年第10期1772-1785,共14页中国科学（技术科学英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos. 40425004, 40528005, 40390152);the National Basic Research Program of China (Grant No. 2006CB806305)

摘　　要：Based on observations obtained by Cluster C1, GOES 10, 12, and Polar, the global ULF wave properties are studied during the recovery phase of a very intense magnetic storm-Halloween storm (October 31, 2003, 21:00–23:00 UT). The results indicate that the ULF waves’ properties observed by different satellites, such as amplitude, period, etc. show large variations. This can be interpreted as that Field Line Resonance (FLR) might take place in the region where Cluster C1 passed. The compressional wave of the cavity mode coupled with FLR’s shear Alfven wave and fed energy to the latter, forming a large-amplitude toroidal mode. From the point of period, Cluster C1 observed the shortest period, GOES 10, 12 observed the middle, while Polar observed the longest. The wave period of toroidal mode observed by Cluster C1 kept almost unchanging when Cluster C1 passed L range from 11.7 to 5.3. Using the Squared Wavelet Coherence analysis method, we estimated that the FLR region in the dayside magnetosphere could expand to at least 4 local time widths. The toroidal mode observed by Polar was a standing wave, while the poloidal mode was a propagating wave, the observation results could be well explained by the waveguide mode theory. Since the solarwind speed V <SUB>x</SUB> was &#8722;800 km/s and the dynamic pressure varied little, we speculated that the source of the ULF wave was the Kelvin-Helmholtz instability at the magnetopause triggered by high speed solarwind.

关 键 词：magnetic STORM ULF wave poloidal MODE TOROIDAL MODE compressional MODE cavity MODE Field Line Resonance (FLR) 

分 类 号：P318.22[天文地球—固体地球物理学]